Update About tab of ConfigTool

- Made About tab the last tab in the list
- General tab now the default tab
- Freeseer logo moved to right side
- Modified test for default widget
- About tab layout similar to Recording
Update the testing doc page from unittest to pytest

The contributor testing page contained examples of writing UnitTest
unit tests. The references and examples have been updated with pytest
information instead of UnitTest information. Therefore, new or existing,
contributors will now have a brief introduction to writing and running
the Freeseer pytest unit tests.

Fix #566
Related #420
Related #484
Update docs README

Updated Sphinx installation instructions in README since Sphinx is now
in dev-requirements.txt.

Related to #575

[skip ci]
Moved recording routes from server.py to recording.py
Created recording Blueprint
Added recording blueprint
Move recording logic from server.py to recording.py: recording plugin attributes now member of recording blueprint instead of app.
Configuration logic brought to recording.py class, changes to test framework made
Recording configuration logic wrapped in decorator to fire automatically during first api call.
http_response object creation and error handling performed by decorator
Moved http_response decorator and error classes to server.py
Minor refactoring of endpoint logic
Add comments and improve code clarity.
Return JSON response on http error
Changes made based on code review. Re-organized imports, improved docstrings, comments, removed errant code
Changes based on code review, aligned arguments, organized import statements, formatting issues.